Synchronizing system.



W. A. FRICKE.

SYNGHRONIZING SYSTEM.

APPLICATION FILED 0CT.17,1910.

1 ,0 1 6, 6 1 8. Patented Feb. 6, 1912.

UNITED STATES PATENT OFFICE.

WILLIAM A. FRICKE, OF CHICAGO, ILLINOIS, ASSIGNOR T0 MONARCH TELEII-IOI\TE MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SYNCHRONIZING SYSTEM.

Specification of Letters Patent.

Patented Feb. 6, 1912.

Application filed October 17, 1910. Serial I io. 587,583.

To all whom it may concern Be it known that I, TILLIAM A. Fnioxn, citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Synchronizing Systems, of which the following is a full, clear, concise, and exact description, reference being had to theaccompanying drawings, forming a part of this specification.

My invention relates to systems and apparatus for synchronizing indicating devices, such for example, as clocks.

My invention, generally speaking, comprises an equipment which includes the clock or otherindicating device, and mechanism for synchronizing the clock which is jointly controlled by the clock and an instrumentality which is brought into operation when the synchronism is to be effected.

My invention is of particular service in connection with those synchronizing systems in which. telephone lines are employed as synchronizing circuits, though I do not wish to be limited to an organization that includes telephone lines, since other circuits than telephone line circuits may be employed to advantage in practicing my invention.

Generally speaking, the system made in accordance with my invention may bedescribed as including a synchronizing circuit, such as a telephone line circuit, a switching device periodically operated by the clock, or other indicating device, to close or change said synchronizing circuit, and electromagnetic apparatus-for directly causing the synchronizing function which is 'jointl controlled by the switching device that is governed by the clock and the master-synchronizing element that is. brought into play each time synchronism is to take place.

I will explain my invention more fully by reference to the accompanying drawing showing the preferred embodiment thereof, and in which Figure 1 is a diagrammatic View of so Y much of a telephone exchange system as is necessary to understand the operation of the synchronizing mechanism that is shown in connect-ion therewith. Fig. 2 is a v1ew generally similar to Fig. 1, the circuit being slightly modified. Fig. 3 is a diagrammatic view showing one of many types of electro-mechanical synchronizing devlces that may enter into-the equipment.

Like parts are indicated by similar characters of reference throughout the different figures.

I have shown in each of Figs. 1 and 2,

one of many types of telephone lines, each telephone line illustrated being shown as including two metallic sides a b that extend from a substation to an exchange, each substation including a well recognized telephonic equipment comprising a telephone switch hook c, a telephone receiver (5 included in-a closed local secondary circuit, a telephone transmitter e and a primary coil f that is connected, together with the telephone transmitter, in circuit bet-ween the sides a b of the line, when the receiver is removed from its switch hook. A signal receiver 9 is shown in circuitwith a condenser h, the signal receiver and condenser being included in bridge of the associate line to enable the signal receiver to respond to ringing currents impressed upon the line from a generator 2' at the exchange, all as'is well understood by those skilled in the art.

The telephone exchange equipment illustrated in each of Figs. 1 and 2, also in-.

1), thereby to open the circuit of the line signal device 0 when the operator responds to the signal conveyed by said signal device and'which battery m serves to supply talking current to the telephone lines, and also to cause the operation of supervisory signals (not illustrated), all as is Well understood by those skilled in the art.

I have not deemed it necessary to illustrate more of a telephone exchange equipment in Figs. 1 and 2, and while I have illustrated portions of a well recognized telephone exchange system, I do not wish to be limited thereto in all embodiments of my invention.

In each or the telephone exchange equip ments illustrated the battery m is normally constantly connected with the telephone lines so that when the sides of any telephone line thus normally constantly connected with said battery are brought together the circuit will be closed through said battery for operating purposes. Tn the.

the battery m through the upper blade of the switch y, the right hand armature switch of relay p when normal, the side I) of the telephone line, the impedance a, re lay r the contacts w and a: when engaged,

the limb a of the telephone line, the, left hand armature switch of relay p when normal, the line relay 'n, the lower blade of switch y to the right hand terminal of battery m. The clock whose mechanism is to be synchronized periodically closes the main synchronizing circuit at w m, the contacts to and :10 being engaged preferably once a day, say at midnight. Obviously the frequency with which the clock mechanism performs its circuit controlling function may be varied to suit requirements. The relay r is made of high resistance in order to prevent the operation of the line relay and line signal when the circuit is established through the'relay r, though I do not wish to be limited to this characteristic. The relay r, when energized once in twenty-four hours or at other intervals, attracts its armature to efiect an opening in a local circuit that includes a synchronizing magnet s and a' battery t. This local circuit preferably includes another switch, in addition to the armature switch governed by the relay 7, this second switch including a spring 7 brush u and a contact '0 that is presented thereto and engaged therewith as frequently as the circuit 1s established through the re lay r, this engagement terminating before circuit throu h said relay is opened. The

- clock mechanism which actuates the contact 4) also actuates the contact w included in circuit with the relay r in such a manner as to enable the contact 'w to engage a contact spring brush on, so as to enable the closure of the circuit through the relay 1* to occur before the parts u 'v of the local circuit switch are engaged and to cause the opening of the "circuit through the relay '2" after the switch elements a a have become sepa- 1 rated. In this way the local circuit for-the ment, which is to be described, is operated for the purpose of opening or otherwise changing the-main circuit through the relay 1" in order that the armature switch of said relay may bereleased during the time the elements u and a) of the local circuit switch are in engagement, whereby the battery t is permitted, at the instant the master synchronizing device is operated, to energize a synchronizing magnet s, to bring the clock into synchronism. I need not describe any of the mechanism of the synchronizing device which is' illustrated in Fig. 3, as the type of synchronizing device there shown is very familiar to those skilled in the art,

nor do I limit myself to the said synchro nizing mechanism.

The master synchronizing device which I have illustrated comprises a circuit opening and closing switch y, in this instance a manually operated switch to which I do notwish to be limited, which is operated to open the main synchronizing circuit that includes battery m to prevent current from flowing therefrom over the telephone line at that instant when the clock is to be synchronized, at which instant the contacts w and w are in engagement, as are also the contacts -u and q: whereby,at which instant, the armature switch of relay 1' is 'released to bring about the energization of the magnet s with results which have been specified. By causing the engagement of the contacts as and r .before contacts a and "u are engaged and breaking the engagement of the contacts at and o before engagement between the contacts w and w is broken the closure of the circuit through the magnet s is absolutely prevented except through the operation of the master synchronizing device 3 I believe it to be broadly new with me to control the closure and separation of the switches was and u o by the clock, or other indicating device which is to be synchronized, and to cause these switches to cooperate with the balance of the equipment with results which have been set forth. When the device is in no need of synchronism, its timing being correct, inefiective synchronizing action will arise when the contacts a and m engage the middles of the contacts '0 and 10 respectively providing the master synchronizing device y is at that time operated. The contact w is elongated upon each side of its middle.

action must cease before the contacts so and a: separate. The contact 11 is adapted for engagement with the contact u throughout a predetermined interval of lesser duration than the contacts to and m as has been made clear, the lesser interval being comprised within the greater interval whereby the main synchronizing circuit may be automatically adjusted preparatory to the operation of the master synchronizing devicey and whereby the time at which the master synchronizing device is to be operated may be timed exactly. If the contact to did not engage the contact 0: before the contact o engaged the contact a, the mere closure of the contacts 4; and u would effect synchronism, upon the denergized condition of the magnet 10, which might be false. If the contact w did not leave the contact a; after the contact 4) left the contact u, then another synchronizing action, which would positively be an incorrect action, would occur. By means of my invention the time indicating device is not permitted automatically to take part in its false, synchronism. By the arrangement set forth, the common battery may be in normal circuit relation with the line so that the same line may be used for a common battery telephone system that is also used for the synchronizing system. As I have shown my invention embodied in connection 'with telephone exchange equipment, I have included an impedance coil 2 in circuit with the relay 0* for the purpose of sutiiciently obstructing current from the ringing generator 2' to prevent false operation of the relay 7* when it is included in circuit with the battery m.

As shown and described, the contacts v and u close the local or secondary'synchronizing circuit that includes the synchronizing magnet s after the normally open break in the main synchronizing circuit has been closed at w 00. As will also be understood from the previous description, thesecondary or local synchronizing circuit is opened by the separation of the contactsv a before the main synchronizing circuit is opened at the contacts w as. In this way the armature switch of the relay 'r' is operated, due to the closure of the main synchronizing circuit including said relay before there is opportunity to close the local synchronizing circuit at v u and the closure of such local synchronizing circuit is prevented, as a mere consequence of the engagement of the contacts w and m at any time the contacts 12 and u are engaged, owing to the attraction of the armature switch of relay 7' during all of that time that the contacts a and u are engaged. The only wa efiected is by such manipulation or operation of the master synchronizing switching device y as will cause the opening of the in which synchronism can be mainsynchronizing circuit during the time the contacts u and o are in engagement, whereupon the local synchronizing circuit that includes the synchronizing magnet s will be closed owing to the release of the armature of relay r. By providing the combination of two sets of contacts 'w m and u 2) and associating with the contacts a c the armature switch of relay 7', I am enabled to use non-polarized elcctro-magnetic mechanism 1' and am able to exclude said electromagnetic mechanism from the influence of the common battery except at the time when such common battery needs to be included in the main synchronizing circuit. In the example which has been chosen the electromagnet 1' is included in circuit with the common'battery 'm for a short interval of time in each period of twenty-four hours.

'The equipment shown in Fig. 2 is in all essential respects similar to that shown in Fig. 1. There is a slight modification however, in the location of the master synchronizing element 3 and the circuit which it governs. While in Fig. 1 the main synchronizing circuit governed by the device y is metallic, in Fig. 2, said circuit is grounded, only one limb of the telephone line, namely, limb a, being employed for establishing a main synchronizing circuit through the relay 7'. The system of Fig. 2 possesses an advantage over the system of Fig. 1 in that, with the first system, conversation is not interrupted when the master synchronizing device 3 is operated, whereas, in the second system, such conversation is interrupted. While the relay 1' is preferably non-polarized, I do not wish to be limited to a nonpolarized relay.

Having shown and particularly described two embodiments of my invention to which I do not wish to be limited, I claim as new anddesire to secure by Letters Patent:

A synchronizing system including an indicating device that is tobe synchronized; a main synchronizing circuit including a source of current normally connected between its sides; a switch located at the sta tion of the indicating device and included in the main synchronizing circuit, the closure and separation of the contacts of this switch being governed by the indicating de-.

ioa

chronizing circuit and governed in turn by the indicating device and the first aforesaid magnet, the switch which is operated by the indicating device to take part in governing the main synchronizing circuit and the portion of the switching mechanism operated by the indicating device for taking partin the cont-r01 of the local synchronizing circuit having individual cont-acts that are so related that the contacts of the switch that takes part in governing the main synchronizing circuit are engaged and separated respectively before and after the engagement and separation of the contacts of the said switching mechanism portion that 15 WILLIAM A. FRICKE. Witnesses G. L. CRAGG, ETTA L. WHITE. 

